Introduction to SQL Module 1.

1. SQL200 Based on SQL Clearly Explained by Jan Harrington SQL Programming Module 1 – Relational Database Background, Basic Single Table Retrieval Operations

2. SQL200 P.O. Box 6142 Laguna Niguel, CA 92607 949-489-1472 http://www.d2associates.com [email_address]

7. Relational Database Table

9. Relational Database with constraints

10. Database Management Systems Positioning Chart VLDB Enterprise Workgroup Single user Spreadsheet # Users Cost

11. System Architecture Access MDB File Server Architecture Access

12. System Architecture Oracle DB Visual Basic App Client/Server Architecture Access  SQL 

13. System Architecture Oracle DB Browser Web Architecture Web Server  SQL 

21. SQL Statement Processing Parse Validate Optimize Access Plan Execute

25. SELECT Basic Syntax ( Projection ): Select <column-list> or <*> From <table-list>

26. SELECT Basic Example ( Projection ): select customer_last_name, customer_street from customers

27. MS Access SQL Query

29. SQL Server Query

30. SELECT with Where Clause Example ( Restriction plus Projection ): Select <column-list> From <table-list> Where <selection-criteria>;

31. SELECT with Where Basic Example ( Restriction plus Projection ): select customer_last_name, customer_street from customers where customer_last_name = “Jones”

32. Select with Where

34. Complex Predicates Follow normal boolean logic Select customer_last_name, customer_street From customers Where (customer_last_name = ‘Jones’ or customer_last_name = ‘Smith’)and customer_state=‘NY’

35. Select with Complex Where

36. Complex Where Result

39. IN Select * From customers Where customer_last_name in (“Rizzo”, “Jones”, “Garcia”) The list in parentheses can be replaced by a subquery. We will study this later.

40. SQL Where Clause with IN

41. IS NULL Select * From customers Where customer_street IS NULL SQL uses three valued logic. Must use IS NULL to test for unknowns. A null is NOT the same as blank or empty.

43. BETWEEN Select * From orders Where order_date BETWEEN #1/1/99# and #12/31/99# Note: date formats vary from product to product. Above is Access syntax, SQL Server uses single quotes. Ex: ‘1/1/99’

44. Where with Between

45. Removing Duplicates Select DISTINCT customer_city From customers List once each city in which there are customers Removes duplicate rows from result set

46. Removing Duplicates

47. Sorting – ORDER BY DESC will sort in descending order Basic syntax : Select <column list> From <table list> Where <selection criteria> Order by <column list> [DESC]

48. Sorting – ORDER BY Select * From customers Order by customer_state, customer_city Example: List all records sorted by state, city

49. Sorting Results with Order By

50. Selecting Top Records Select Top 5 (or top 25 percent) Customer_last_name , contact_zip From customers Order by customer_zip desc ; List largest 5 zips or top 25 % of them…